5,616 research outputs found

    Testing and validating the CERES-wheat (Crop Estimation through Resource and Environment Synthesis-wheat) model in diverse environments

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    CERES-Wheat is a computer simulation model of the growth, development, and yield of spring and winter wheat. It was designed to be used in any location throughout the world where wheat can be grown. The model is written in Fortran 77, operates on a daily time stop, and runs on a range of computer systems from microcomputers to mainframes. Two versions of the model were developed: one, CERES-Wheat, assumes nitrogen to be nonlimiting; in the other, CERES-Wheat-N, the effects of nitrogen deficiency are simulated. The report provides the comparisons of simulations and measurements of about 350 wheat data sets collected from throughout the world

    Remaining Challenges in Tanzania's Efforts to Eliminate Iodine Deficiency.

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    To determine iodine levels in salt and iodine deficiency prevalence in school-aged children in 16 districts in Tanzania with previous severe iodine deficiency. A cross-sectional study in schoolchildren. Systematic probability sampling was used to select schools and subjects for goitre assessment and urinary iodine determination. Sixteen districts randomly selected from the 27 categorised as severely iodine-deficient in Tanzania. The study population was primary-school children aged 6-18 years who were examined for goitre prevalence and urinary iodine concentration (UIC). Salt samples from schoolchildren's homes and from shops were tested for iodine content. The study revealed that 83.3% of households (n=21,160) in the surveyed districts used iodised salt. Also, 94% of sampled shops (n=397) sold iodised salt, with a median iodine level of 37.0 ppm (range 4.2-240 ppm). Median UIC in 2089 schoolchildren was 235.0 microg l(-1) and 9.3% had UIC values below 50 microg l(-1). The overall unweighted mean visible and total goitre prevalence was 6.7% and 24.3%, respectively (n=16,222). The age group 6-12 years had the lowest goitre prevalence (3.6% visible and 18.0% total goitre, n=7147). The total goitre prevalence had decreased significantly in all districts from an unweighted mean of 65.4% in the 1980s to 24.3% in 1999 (P<0.05). We believe this difference was also biologically significant. ConclusionThese findings indicate that iodine deficiency is largely eliminated in the 16 districts categorised as severely iodine-deficient in Tanzania, and that the iodine content of salt purchased from shops is highly variable

    Spatially resolved spectroscopy of Coma cluster early-type galaxies - II:the minor axis dataset

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    We present minor axis, off set major axis and one diagonal long slit spectra for 10 E and S0 galaxies of the Coma cluster drawn from a magnitude-limited sample studied before. We derive rotation curves, velocity dispersion profiles and the H-3 and H-4 coefficients of the Hermite decomposition of the line of sight velocity distribution. Moreover, we derive the line index profiles of Mg, Fe and Hbeta line indices and assess their errors. The data will be used to construct dynamical models of the galaxies and study their stellar populations

    Η εφαρμογή των συζεύξευων σε ακραία υδρομετεωρολογικά φαινόμενα

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    Flies are important arthropod pests in intensive animal facilities such as cattle feedlots, with the potential to cause production loss, transmit disease and cause nuisance to surrounding communities. In the present study, seasonal population dynamics of three important nuisance flies, namely house flies (Musca domestica L.), bush flies (M. vetustissima Walker) and stable flies (Stomoxys calcitrans L.) (Diptera: Muscidae), were monitored on cattle feedlots in south-eastern Queensland, Australia, over 7 years. Musca domestica was by far the dominant species, comprising 67% of the total flies trapped. Models were developed to assess the relationship between weather parameters and fly abundance and to determine whether population trends could be predicted to improve the timing of control measures. For all three species, there were two main effects, namely time-of-year (mainly reflected by minimum temperatures and solar radiation) and rainfall. The abundance of all three species increased with increasing temperature and rainfall, reaching a peak in summer, before decreasing again. Rainfall events resulted in significantly elevated numbers of M. domestica for up to 5 weeks, and for 1 week for M. vetustissima. Peak fly numbers were predicted by the model to occur in spring and summer, following 85-90-mm weekly rainfall. The population dynamics of S. calcitrans were least influenced by rainfall and it was concluded that weather variables were of limited use for forecasting stable fly numbers in this environment and production system. The models provide a useful tool for optimising the timing of fly-control measures, such as insecticide or biopesticide applications, adding to the efficiency of integrated control programs

    Understanding the contribution of target repetition and target expectation to the emergence of the prevalence effect in visual search

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    Behavior in visual search tasks is influenced by the proportion of trials on which a target is presented (the target prevalence). Previous research has found that when target prevalence is low (2% prevalence), participants tend to miss targets, compared with higher prevalence levels (e.g., 50% prevalence). There is an ongoing debate regarding the relative contribution of target repetition and the expectation that a target will occur in the emergence of prevalence effects. In order to disentangle these two factors, we went beyond previous studies by directly manipulating participants’ expectations regarding how likely a target was to appear on a given trial. This we achieved without using cues or feedback. Our results indicated both target repetition and target expectation contribute to the emergence of the prevalence effect

    Tweeting transit : an examination of social media strategies for transport information management during a large event

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    Social media platforms are seeing increasing adoption by public transport agencies, as they provide a cost-effective, reliable, and timely mechanism for sharing information with passengers and other travellers. In this paper, we use a case study of the @GamesTravel2014 Twitter account to evaluate how this social media platform was used over the course of the 2014 Commonwealth Games in Glasgow, Scotland to provide and share transport-related information and respond to information requests. The case study provides an exemplar for the public co-ordination of information from multiple partners in a complex environment during a time of transport disruption. We evaluate both the structure and intent of the @GamesTravel2014 social media strategy via interviews with involved parties and an analysis of Tweets related to the account. Findings indicate the potential for future applications of social media by transport operators and authorities in producing a more effective network of communication with passengers

    Data Geologi dan Geofisika Selat Lembeh sebagai Pendukung Pengembangan Infrastruktur Pelabuhan

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    Selat Lembeh sepanjang 16 km dengan lebar sekitar 1 km mempunyai kedalaman laut mencapai 380 m di bagian utaranya, memasuki selatnya mendangkal (20 m) dan ke arah selatannya mendalam (120 m). Dasar laut Selat Lembeh ditutupi oleh sedimen permukaan pasir kerikilan dan kerikil pasiran yang berkomposisi volkanoklastik dan bioklastik bersifat gampingan. Ke dua jenis sedimen ini relatif mempunyai kesesuaian dengan hasil interpretasi sidescan sonar dan seismik, masing-masing sebagai pasir dan sedimen berbutir sedang-kasar (Runtunan D). Daratannya, berdasarkan peta geologi Daerah Bitung dan sekitarnya didominasi oleh batuan gunungapi muda dengan kemiringan pantai antara 0-5o dan tidak ditemukan adanya indikasi sesar. Daerah penelitian mempunyai besaran kegempaan magnitudo kecil dan tsunami terlindung oleh Pulau Lembeh. Kawasan ini berdasarkan peta hidrogeologi termasuk kedalam akuifer setempat, produktif sampai produktif sedang penyebaran luas. Data dasar geologi dan geofisika ini sangat berperan dalam pengembangan Selat Lembeh terutama rencana pengembangan infrastruktur di kawasan Bitung dan sekitarnya. Kata kunci: Kedalaman laut, sedimen permukaan, batuan gunungapi muda, topografi, akuifer dan pengembangan Selat Lembeh.The Lembeh Strait with a length of 16 km and a width of about 1 km has a depth of 380 m in its northern part, entering the strait has a shallow depth of 20 m and to the south it has a depth of 120 m. The seabed of the Lembeh Strait is covered by surface sediment of gravelly sand and sandy gravel formed by volcanoclastic and bioclastic materials. The two types of sediments are relatively similar to the results of the side scan sonar and seismic interpretations, each of which is sand and medium-coarse grain sediments (Sequence D). In the mainland, based on the geological data of the Bitung Region and its surroundings, its lithology is dominated by young volcanic rocks with a slope on the coast between 0-5o and no indications of faults were found. This area is valued of seismicity relatively small magnitude and safe from tsunami waves because it is protected by Pulau Lembeh. This area based on hydrogeological data is classified into local aquifers, productive to medium productive with wide distribution. The basic data of the geological and geophysical aspects play a part in the development of the Lembeh Strait, especially the infrastructure development plan in the Bitung area and its surroundings

    Substructure in the Coma Cluster: Giants vs Dwarfs

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    The processes that form and shape galaxy clusters, such as infall, mergers and dynamical relaxation, tend to generate distinguishable differences between the distributions of a cluster's giant and dwarf galaxies. Thus the dynamics of dwarf galaxies in a cluster can provide valuable insights into its dynamical history. With this in mind, we look for differences between the spatial and velocity distributions of giant (b18) galaxies in the Coma cluster. Our redshift sample contains new measurements from the 2dF and WYFFOS spectrographs, making it more complete at faint magnitudes than any previously studied sample of Coma galaxies. It includes 745 cluster members - 452 giants and 293 dwarfs. We find that the line-of-sight velocity distribution of the giants is significantly non-Gaussian, but not that for the dwarfs. A battery of statistical tests of both the spatial and localised velocity distributions of the galaxies in our sample finds no strong evidence for differences between the giant and dwarf populations. These results rule out the cluster as a whole having moved significantly towards equipartition, and they are consistent with the cluster having formed via mergers between dynamically-relaxed subclusters.Comment: 23 pages, 6 figures, to appear in Ap

    Randomized Efficacy Trial of a Micronutrient-Fortified Beverage in Primary School Children in Tanzania.

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    Dietary supplements providing physiologic amounts of several micronutrients simultaneously have not been thoroughly tested for combating micronutrient deficiencies. We determined whether a beverage fortified with 10 micronutrients at physiologic doses influenced the iron and vitamin A status and growth of rural children (aged 6-11 y) attending primary schools. In this randomized, double-blind, placebo-controlled efficacy trial, children were assigned to receive the fortified beverage or an unfortified beverage at school for 6 mo. There were nonsignificant differences at baseline between children in the fortified and nonfortified groups in iron status, serum retinol, and anthropometry. At the 6-mo follow-up, among children with anemia (hemoglobin < 110 g/L), there was a significantly larger increase in hemoglobin concentration in the fortified group than in the nonfortified group (9.2 and 0.2 g/L, respectively). Of those who were anemic at baseline, 69.4% in the nonfortified group and 55.1% in the fortified group remained anemic at follow-up (RR: 0.79), a cure rate of 21%. The prevalence of children with low serum retinol concentrations (< 200 microg/L) dropped significantly from 21.4% to 11.3% in the fortified group compared with a nonsignificant change (20.6% to 19.7%) in the nonfortified group. At follow-up, mean incremental changes in weight (1.79 compared with 1.24 kg), height (3.2 compared with 2.6 cm), and BMI (0.88 compared with 0.53) were significantly higher in the fortified group than in the nonfortified group. The fortified beverage significantly improved hematologic and anthropometric measurements and significantly lowered the overall prevalence of anemia and vitamin A deficiency
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